Acquired pure red-cell aplasia (PRCA) is an uncommon disorder of erythrocytopoiesis that can develop in association with thymic tumors. We present the very rare case of a severely anemic 62-year-old man with PRCA and a concurrent neuroendocrine carcinoid tumor of the thymus. The anterior mediastinal thymus tumor was completely excised, and following histological and immunohistochemical analyses (…

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Acquired pure red-cell aplasia (PRCA) is an uncommon disorder of erythrocytopoiesis that can develop in association with thymic tumors. We present the very rare case of a severely anemic 62-year-old man with PRCA and a concurrent neuroendocrine carcinoid tumor of the thymus. The anterior mediastinal thymus tumor was completely excised, and following histological and immunohistochemical analyses (showing positive staining for cytokeratin, chromogranin A, synaptophysin, and neuron-specific enolase) the diagnosis of a (grade I; T(1)N(0)M(0)) typical carcinoid tumor of the thymus was made. Postoperatively the anemia persisted despite no signs of residual tumor on CT chest. A hematological work up found: normocellularity with <0.5% erythroblasts and preserved megakaryocytopoiesis and granulocytopoiesis in a trephine biopsy; reduced numbers of Colony Forming Unit Erythroid (CFU-E) and normal numbers of Burst-Forming Unit Erythroid (BFU-E) in bone marrow colony-forming assays; a markedly increased level of serum erythropoietin; normal T and B-cell numbers with a normal CD4/CD8 ratio; and no clonal T-cell receptor -gamma and -delta gene rearrangement) The patient responded favorably to a therapeutic trial of glucocorticoid immunosuppressive treatment (prednisone 1 mg/kg/day) with a normalization of the reticulocyte count and hematocrit, suggesting an immunologic mechanism for the PRCA. Though the exact mechanisms underlying the association between the PRCA and the carcinoid tumor of the thymus remain unknown.

We showed that the content of reticulocyte hemoglobin (CHr) is a reliable measure of iron status with regard to erythrocytopoiesis in chronic dialysis status. The mean CHr level was 32.3 +/- 2.2 pg in dialysis patients and CHr was significantly correlated with the conventional parameters of iron deficiency. We aimed to utilize the measurement of CHr levels to monitor iron status in clinical pract…

We showed that the content of reticulocyte hemoglobin (CHr) is a reliable measure of iron status with regard to erythrocytopoiesis in chronic dialysis status. The mean CHr level was 32.3 +/- 2.2 pg in dialysis patients and CHr was significantly correlated with the conventional parameters of iron deficiency. We aimed to utilize the measurement of CHr levels to monitor iron status in clinical practice. We measured CHr, iron parameters, and the intrinsic EPO concentration in non-dialysis CRF patients to clarify the alterations in CHr levels that occur as renal anemia progresses. CRF patients who visited our out-patient clinic (n = 189) were included in the study. Iron deficiency was defined by the transferrin saturation and ferritin levels. Conventional red blood cell parameters and CHr levels were measured using an ADVIA120 autoanalyzer (Bayer Medical, USA). The mean CHr value of the non-dialysis patients (creatinine clearance less than 70 ml/min) was 32.7 pg, which did not differ significantly from that of the dialysis patients. Significant correlations were found between CHr and TSAT (r = 0.032, p < 0.0177), unlike the correlation with intrinsic EPO levels. Overall, 11% of the patients were diagnosed as having iron deficiency. There was a positive correlation between CHr and serum creatinine levels. Non-dialysis CRF patients treated with rHuEPO at the dose of 24,000 U/month showed different CHr levels compared with other patients (less than 24,000 U/month). It is possible that rHuEPO treatment in non-dialysis patients affects iron dynamics. In conclusion, CHr is an easily measurable and reliable marker of iron status in non-dialysis CRF patients. Moreover, the CHr level was also sensitive to iron alternations in non-dialysis CRF patients under rHuEPO treatment. Accordingly, if long-acting EPO is available for non-dialysis CRF patients, the CHr value is likely to be indicative of the need for iron supplementation.

Adult male Wistar rats were exposed for 2 h a day, 7 days a week for up to 30 days to continuous 2,450 MHz radiofrequency microwave (rf/MW) radiation at a power density of 5-10 mW/cm(2). Sham-exposed rats were used as controls. After ether anesthesia, experimental animals were euthanized on the final irradiation day for each treated group. Peripheral blood smears were examined for the extent of g…

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Adult male Wistar rats were exposed for 2 h a day, 7 days a week for up to 30 days to continuous 2,450 MHz radiofrequency microwave (rf/MW) radiation at a power density of 5-10 mW/cm(2). Sham-exposed rats were used as controls. After ether anesthesia, experimental animals were euthanized on the final irradiation day for each treated group. Peripheral blood smears were examined for the extent of genotoxicity, as indicated by the presence of micronuclei in polychromatic erythrocytes (PCEs). The results for the time-course of PCEs indicated significant differences (P<0.05) for the 2nd, the 8th and the 15th day between control and treated subgroups of animals. Increased influx of immature erythrocytes into the peripheral circulation at the beginning of the experiment revealed that the proliferation and maturation of nucleated erythropoietic cells were affected by exposure to the 2,450 MHz radiofrequency radiation. Such findings are indicators of radiation effects on bone-marrow erythropoiesis and their subsequent effects in circulating red cells. The incidence of micronuclei/1,000 PCEs in peripheral blood was significantly increased (P<0.05) in the subgroup exposed to rf/MW radiation after eight irradiation treatments of 2 h each in comparison with the sham-exposed control group. It is likely that an adaptive mechanism, both in erythrocytopoiesis and genotoxicity appeared in the rat experimental model during the subchronic irradiation treatment.

Regular measurement of HbA1c (percentage) is an essential component of modern diabetes care. Factors that affect the life span of erythrocytes will also influence HbA1c results. In this study, we describe two patients with IDDM, whose regularly determined HbA1c values were considerably decreased with the concomitant use of two related sulfonamide drugs, sulfasalazine and dapsone. The fall in HbA1…

Regular measurement of HbA1c (percentage) is an essential component of modern diabetes care. Factors that affect the life span of erythrocytes will also influence HbA1c results. In this study, we describe two patients with IDDM, whose regularly determined HbA1c values were considerably decreased with the concomitant use of two related sulfonamide drugs, sulfasalazine and dapsone. The fall in HbA1c results is explained by increased erythrocytopoiesis as a product of drug-induced hemolysis. Fructosamine concentrations are not affected by hemolysis and reflected glycemic control better. We conclude that under conditions of persistent (subclinical) hemolysis, as occurs during the use of sulfonamides, HbA1c is not a reliable indicator of glycemic control.

Simultaneous or sequentional but spontaneous occurzence of polycythaemia vera and chronic lymphocytic leukaemia is very unusual. Moreover, the pathogenesis of these two malignancies has not yet been explained. The authors discribed a 64-year-old man with remarkable mild clinical course of polycytheameia vera associated with chronic lymphocytic leukaemia, lasting more than 5 years. Bone-marrow cel…

Simultaneous or sequentional but spontaneous occurzence of polycythaemia vera and chronic lymphocytic leukaemia is very unusual. Moreover, the pathogenesis of these two malignancies has not yet been explained. The authors discribed a 64-year-old man with remarkable mild clinical course of polycytheameia vera associated with chronic lymphocytic leukaemia, lasting more than 5 years. Bone-marrow cell culture revealed spontaneous growth of erythroblast progenitors (BFU-E, CFU-E) and reduced number of haemopoietic progenitorus, mainly due to lymphocyte bone marrow infiltration. The patient plasma selectively inhibited growth of the BFU-E and CFU-E progenitor cells of normal bone-marrow, suggesting that some inhibitor of erythrocytopoiesis influenced supression and/or control of one disease by the other.

Interleukin-11 (IL-11), a stromal cell-derived cytokine, has been known to act widely in hematopoietic and non-hematopoietic systems. IL-11 supports the growth of certain types of plasmacytoma and hybridoma cells, acts with interleukin-3 (IL-3) in shortening the Go period of early progenitors. IL-11 supports megakaryocyte colony formation and maturation, and acts as an autocrine growth factor in …

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Interleukin-11 (IL-11), a stromal cell-derived cytokine, has been known to act widely in hematopoietic and non-hematopoietic systems. IL-11 supports the growth of certain types of plasmacytoma and hybridoma cells, acts with interleukin-3 (IL-3) in shortening the Go period of early progenitors. IL-11 supports megakaryocyte colony formation and maturation, and acts as an autocrine growth factor in megakaryoblastic cell lines. In addition, IL-11 stimulates erythrocytopoiesis, enhances antigen-specific antibody responses, induces the synthesis of acute phase proteins, inhibits lipoprotein lipase activity and adipocyte differentiation, and promotes neuronal development. Administration of rhIL-11 to mice resulted in an increase of neutrophils and platelets. The human IL-11 gene is localized at 19q13.3-13.4, and codes 199 amino acids and 23 kDa with no N glycosylation. Its receptor and signal transduction share partially those of interleukin-6 (IL-6). Further analysis of its role in normal and pathological state is necessary to determine the exact function and its application for clinical uses.

Blood counts, bone marrow cytology and iron status in 13 patients with severe renal anemia assessed prior to and after recombinant human erythropoietin treatment. The mean increase of PCV after 8 weeks of treatment was 50%. Simultaneously, we observed a fourfold increase of the reticulocyte count. This increment correlated with a twofold increase of the percentage of bone marrow erythroblasts. We…

Blood counts, bone marrow cytology and iron status in 13 patients with severe renal anemia assessed prior to and after recombinant human erythropoietin treatment. The mean increase of PCV after 8 weeks of treatment was 50%. Simultaneously, we observed a fourfold increase of the reticulocyte count. This increment correlated with a twofold increase of the percentage of bone marrow erythroblasts. We also observed an increment of the relative number of erythropoietin-dependent early erythroblasts. The tager PCV of 0.30 was achieved in 4 of 5 predialysis patients, but was not achieved in 8 hemodialysis patients because they had an "absolute" bone marrow erythroblastopenia. In conclusion, conventional hematologic examination revealed that application of recombinant human erythropoietin leads to improvement of erythrocytopoiesis in different stages of chronic renal failure.

An ultrastructural study was performed on bone marrow specimens in 10 patients (5 males/5 females, median age 53 years) with primary (essential) thrombocythemia (PTH) and an excessive elevation of the platelet count (1,625 +/- 783 x 10(9)/l). In contrast to a not severely altered neutrophilic granulo- and erythrocytopoiesis, megakaryocytes showed conspicuous large to giant forms. These were chara…

An ultrastructural study was performed on bone marrow specimens in 10 patients (5 males/5 females, median age 53 years) with primary (essential) thrombocythemia (PTH) and an excessive elevation of the platelet count (1,625 +/- 783 x 10(9)/l). In contrast to a not severely altered neutrophilic granulo- and erythrocytopoiesis, megakaryocytes showed conspicuous large to giant forms. These were characterized by a highly lobulated nucleus containing several nucleoli and an extensive intermediate zone of the cytoplasm with many Golgi fields, numerous profiles of the so-called demarcation membrane system and an abundance of alpha-granules and some dense bodies. Our results demonstrate that ultrastructure of the megakaryocytes in PTH does not reveal gross abnormalities, but features which are compatible with an enforced thrombocytogenetic activity in accordance with the excessively elevated platelet count. Similar changes have been described in animal experiments with induced thrombocytopenia and stimulation of platelet shedding. Evaluation of thrombocytogenesis suggests that it may be mediated by a process of fragmentation with partitioning of the extensive intermediate zone into numerous prospective platelet territories followed by segregation.